The manufacture of golf balls typically involves a series of sequential processes performed at different processing stations, typically spatially separated one from another. For example, golf balls typically have a core and a dimpled pattern for a cover.
Each process must be carefully monitored for quality assurance purposes. Inspections are typically performed for assuring a desired confidence level in production quality. Quality control criteria, may be in place as well. The manufacturer may further choose to manually inspect the entire lot being inspected if a given number of defective balls are found therein. Moreover, if a major defect is found, such as a significant variance in a physical property like weight or compression which could affect performance or durability, the manufacturer may choose to shut down the entire system.
There has been a continuing desire to achieve high production rates. Because automated apparatus typically may function faster than human operators, there has been an ongoing goal to reduce, if not eliminate, human intervention during the manufacturing process. Thus, performance or physical property testing is typically performed at a separate automated processing station functioning at optimal efficiency and speed so that the overall production rate is maintained at the desired high level. For instance, given the quality control standards necessary to meet production standards and the high production rates of golf ball manufacturing plants, actions to correct a malfunction in the automated processing equipment should be taken as soon as possible to reduce the number of defective golf balls produced. The sooner a defect is detected, the lower the likelihood of reaching the pre-determined number of defects initiating a need for further quality assurance corrective measures that need to be taken. Accordingly, there is a need for speedy and efficient testing of physical properties of golf balls and golf ball cores so that any manufacturing problem may be corrected almost immediately to reduce the further production of defective balls.
A variety of automated inspection systems and methods are known for use in quality control of automated processing stations. Inspection apparatuses currently known for inspecting spherical objects generally require rotation of the object and cannot account for the three-dimensional contoured surface. For example, U.S. Pat. No. 5,703,687 to Kumagai et al. shows an automated inspection system which requires the addition of golf ball rotating equipment to the usual automated conveying equipment used to convey golf balls from an automated processing apparatus.
The spherical shape of the golf ball makes automated inspection of the three-dimensional surface difficult to achieve by the two-dimensional analysis techniques of inspection systems used in other industries. The addition of contours, in the form of dimples, on an already spherical object further complicates automated inspection thereof. Standard machine vision inspection systems using a template based inspection technique desensitized to prevent false rejections of prints or contoured surfaces are also de-sensitized to small defects on the edge of the print and thus are not completely effective. Prior art inspection systems have not been successful at achieving the proper combination of machine vision components, lighting, optics, and image processing techniques necessary to successfully analyze the printed images on golf balls to provide an on-line inspection system.
Thus, the golf ball manufacturing industry has heretofore relied on manual inspection to determine the quality of the various processes performed in manufacturing a golf ball. However, because the high production rate typically encountered in the industry far exceeds the speed with which manual inspection can be performed, such manual inspection cannot be performed on every ball, thus impeding efficiency, and potentially resulting in a certain number of undetected defective balls. Moreover, manual inspection is not 100% effective, given the possibility of human error or oversight, and may cause the inspected ball to be marred by manual handling.
Thus, although automation of the golf ball manufacturing process has resulted in high production rates, such production rates are subject to the efficiency and speed with which quality inspection may be performed. If inspection is not performed routinely and quickly, a high number of defective products may be produced before appropriate measures are taken to correct the cause of the defect.